Flexible door



March 5, 1957 E. CANN 2,783,833

FLEXIBLE DOOR Filed April 19, 1955 2 Shee'ts-Sheet 1 8 INVENTOR. 3 EDWARD Cm AGEN I.

United States Patent FLEXIBLE DOOR Edward Cann, Summit, N. J.

Application April 19, 1955, Serial No. 502,437

4 Claims. (Cl. 160-354) My invention relates to flexible doors.

Doors of the above type comprise a flexible panel which is secured on one vertical edge, and in some cases also along the top, to a rigid frame which is pivoted and maintained in the closed position by springs. As described in my United States Patent No. 2,279,572, the frame may be in the form of an inverted L and the panel may be a sheet of flexible material, such as rubber or plastic, which is secured along its top edge and one side edge to the frame. In a similar type of construction the panel is in the form of a bulky mattress-like structure formed of an envelope of flexible material, such as rubber, stuffed with a filling material, such as hair. The latter construction is not as flexible as the single sheet construction, but if it is made sufficiently thick it is selfsupporting and the top portion of the supporting frame can be dispensed with.

Although doors of the above types are satisfactory and have come into rather wide use, I have found that under some conditions they have certain disadvantages. More particularly, I have found that if the panel is made sufliciently flexible so as to obtain the full advantages of a flexible door, it is difficult under some conditions to maintain the free edges of the panel in the proper position when the door is in its closed position. This may be due to a difference in pressure of the air on the sides of the door, to wind pressure or, when the door is of the stuffed type, to a temperary deformation of the panel. These difliculties are particularly prevalent at the lower unsupported corner of the panel although they exist along the unsupported edges. In addition, if a rigid frame is not used to support the upper edge of a stuffed type panel there may be a certain amount of sagging and misaligning of the panel which results in an undesirable opening, when the door is in its closed position.

The main object of my invention is to provide such doors with flexible stiffening devices whereby the panels are maintained in their proper position when the door is closed While at the same time maintaining the flexibility of the door.

A more specific object of my invention is to provide a flexible stiffening member which offers an initial resistance against flexing.

A further object is to improve the vertical support of the stuffed type door without appreciably decreasing the flexibility.

Further objects will appear as the description progresses.

In accordance with my invention, I provide such doors with one or more stiffeners each comprising a plurality of rigid vertebra-like members which are held together with tensioning means to form an elongated member which has a certain amount of initial rigidity. in one form of my invention the stiffener comprises a plurality of tubular vertebra-like members which are held in tension by a tension spring which passes through the members and is secured to the end members. I so shape and dimension the vertebra members and apply the tensioning at such a point that the force necessary to flex the stiffener must exceed a certain value before any flexing takes place. For this purpose, I so shape the vertebralike members that the adjacent surfaces thereof engage each other at points spaced some distance from the point at which the tension is applied.

In order that my invention may be clearly understood and readily carried into effect, I shall describe the same in more detail by means of specific examples and with reference to the accompanying drawing in which:

Figure 1 is a side elevation of a flexible door provided with a stiffener according to the invention,

Figure 2 is a sectional fractional view on an enlarged scale of the stiffener used in the door of Figure 1,

Figure 3 is a sectional view of a vertebra member for use in the stiffener of Figure 2,

Figure 4 is a sectional View of another type of vertebra member for use in the stiffener of Figure 2,

Figure 5 is a side elevation of a door of the stuffed type provided with stiffeners,

Figure 6 is a sectional fractional view on an enlarged scale along line 66 of Figure 5,

Figure 7 is a sectional view on an enlarged scale of a portion of a different type of stiffener for use in the door of Figure 5, and

Figure 8 is a side view of one of the vertebra members of the stifiener of Figure 7.

The door illustrated in Figure 1 comprises an inverted L shaped metal frame 1 which is pivoted at the top and bottom of its vertical portion. The frame is provided with a spring mechanism, which is not shown but may be of the construction shown in my above-referred to Patent 2,279,572, whereby the door is held in its closed condition, but may be swung in one or both directions against the spring pressure. Secured to frame 1 by means of rivets or other suitable securing means is a panel 2 of flexible material such as a rubber or plastic. In accordance with the invention, the panel of the door is provided with a stiffener 3 which is fastened to the lower edge of panel 2 by means of several circular brackets 4 secured to the panel by rivets or bolts. One end of stiffener 3 is secured to frame 1 by means of a bracket 5.

As shown more clearly in Figure 2, the stiffener 3 comprises a plurality of vertebra-like members 6 made of metal or other rigid material and provided with a central bore 7. Passing freely through the bores 7 of members 6 is a tension spring 8 whose ends are secured to threaded rods 9 and 9. Rod 9 passes through a hole in bracket 5 and is secured thereto by two nuts 10, a washer 11 being used between the inner nut and the ad jacent member 6. Rod 9' which is threaded over a large part of its length is provided with a washer 11 and a nut 10, which serves to adjust the amount of tension in the spring 8 and thus the flexibility of the stiffener.

The ends of the tubular vertebra-like members 6 are provided with concave surfaces, shown as conical surfaces, whereby the adjacent surfaces contact only at their outer edges, i. e., at some distance from the spring 8. As a result, the stiffener is maintained in its straight position.

Instead of the vertebra-like members 6 I may use tubular members as the member 12 shown in Figure 3 which, instead of having concave end surfaces, is provided on one end surface with an annular rib 13 and on the other surface with an annular grove 14. Rib 13 and groove 14 are of the same diameter, but the cross-sectional diameter of groove 14 is made smaller than that of rib 13 to provide a spacing between adjacent members 12 and an easy pivoting action.

Instead of the members 6 and 12 of Figures 2 and 3 I may use a vertebra-like member 15 of the type shown in Figure 4. Member 15 is stamped from a sheet of metal and has a rib-like circular portion 16 and a circular cavity 17. Similarly to the rib and groove construction of Figure 3, the cross-sectional diameter of the portion 16 is made larger than the width of the cavity 17 to thereby provide spacing between the members 15 and an easy pivoting action.

The door shown in Figures and 6, which is of the stuffed type, comprises a frame in the form of a metal channel 18 which is pivoted at its top and bottom and is provided with suitable means (not shown) to maintain the door in a closed position. The panel of the door is formed of a sheet 19 of fiexible material, such as rubber or plastic, formed into an envelope and having its ends riveted to the frame 18. The space formed within the envelope is filled with a filling material 20, such as animal hair coated with rubber. As shown in Figure 5, the door is provided with seven stiiieners 21 which are of the types described in connection with the Figures 2, 3 and 4.

a The stiffener shown in Figures 7 and 8, which is particularly adapted for use in a door of the type shown in Figure 5, comprises a plurality of vertebra-like members 22. Members 22 are of a rectangular shape and are provided with two holes 23 through which freely pass springs 8 which are of the construction shown in Figure 2 and are similarly secured to the channel frame 18. Similarly to the vertebra-like member 12 of Figure 3, the mem bers 22 are provided with ribs 24 and grooves 25 which serve to space the adjacent members and to provide an easy pivoting action.

it will be noted that, because of the diiferent distances between the springs and pivot points of the stiffener of Figure 7, the stiffening action in a vertical direction will be greater than in a horizontal direction. This is useful in providing additional vertical support to the stuffed panel of the door of Figure 5, without unduly increasing the rigidity in a horizontal direction. If desired, the stiffening may be rotated through 90 whereby the stiffening action in a horizontal plane will be greater than in a vertical plane.

While I have described my invention in connection with specific examples and with reference to certain constructions, I do not wish to be limited thereto as equivalent constructions and modifications will readily present themselves to one skilled in this art.

What I claim is: T

l. A door comprising a'fiexible panel, pivotal means secured to one vertical edge of said panel and stiffening means extending from said vertical edge toward a free edge of the panel, said means including a plurality of vertebra-like members and a tensioning member holding said vertebra-like members in alignment.

2. A door comprising a flexible panel, pivotal means secured to one vertical edge of said panel, and an elongated actuated member having one end secured near said vertical edge and the other end secured near the opposite 4 edge of said panel, said member including a plurality of vertebra members provided With central apertures, a tension spring passing through said apertures with its ends secured to the end vertebra members.

3. A door comprising a flexible panel, pivotal means i secured to one vertical edge of said panel and an elongated actuated stiffening member having one end secured adjacent said free end of said panel and the other end secured adjacent the opposite end, said member comprising a plurality of apertured vertebra members having adjacent surfaces in contact only at points spaced from the apertures, and a tensioning spring passing through the apertures of said vertebra members and having its ends secured to the end vertebra members.

4. A door comprising a frame in the form of an inverted L, a sheet of flexible material having its top and one side edge secured to said frame, and an elongated stiffening member having one end secured near said frame and the other end secured near a free edge of said sheet, said member comprising a plurality of apertured vertebra members and a tension spring passing through the apertuers of said vertebra members with its ends secured to the end vertebra members.

References Cited in the file of this patent UNITED STATES PATENTS 

